Study On Preparation And Properties Of Bi₁₂o₁₇cl₂ Composite Photocatalys

Ag@AgX(X = Cl,Br,I)is a new type of plasma photocatalyst,which has strong activity under visible light,but its stability is poor,and its stability can be improved by combining with other materials.In this study,Bi12O17Cl2 was prepared by hydrothermal method using bismuth nitrate as bismuth,and Ag@AgCl/Bi12O17Cl2,Ag@AgBr/Bi12O17Cl2,Ag@AgI/Bi12O17Cl2 were prepared by two-step synthesis method.XRD and SEM were used to characterize them.The photocatalytic activity was studied under a variety of conditions by a series of photocatalytic degradation experiments,and the degradation mechanism was briefly discussed.The conclusions are as follows:1、Bi12O17Cl2 was prepared by hydrothermal method.The mathematical model of Bi12O17Cl2 photocatalytic degradation of rhodamine B was established by using the response surface method,and the process was optimized.The optimization results show that the model is well fitted and has good predictability.The optimum coding conditions for the degradation of Rhodamine B by Bi12O17Cl2 are as follows:X1=0.265,X2 =-0.235,X3 = 0.669,respectively.The optimum conditions for the degradation of rhodamine B by Bi12O17Cl2 are:The dosage was 32.65mg,the initial concentration was 5.53mg/L,the reaction time was 160.13min.Under this condition,by the equation predicted rhodamine B maximum removal rate of 100%.In order to verify the accuracy of the regression equation,under this condition,three groups of parallel experiments were carried out.The average decolorization rate of rhodamine B was 99.44%,and the error was 0.56%.The results show that the regression equation can reflect the effect of the main factors on the photocatalytic degradation of rhodamine B by Bi12O17Cl2.2、In the experiment of degradation of methylene blue,the photocatalytic effect of Ag@AgCl/Bi12O7Cl2,Ag@AgBr/Bi12O17Cl2 and Ag@AgI/Bi12O17Cl2 prepared by two-step synthesis method were all better than Bi12O17Cl2 and Ag/Bi12O17Cl2.When the concentration of methylene blue is 5 mg/L,The optimum catalyst dosage for Ag@AgCl/Bi12O17Cl2-0.1 is 20 mg;The optimum catalyst dosage for Ag@AgBr/Bi12O17Cl22-0.2 is 30 mg.3、The composite of Ag@AgX(X= Cl,Br,I)can improve the photocatalytic activity of Bi12O17Cl2,in which the amount of compound has a certain effect on it.Ag/AgX/Bi12O17Cl2(X = Cl,Br,I)has a good degradation effect on low concentration of methylene blue solution,and the degradation rate is low at high concentration.In a certain reaction time,the degradation rate increases with time.